Base for a fan



FIG. 1 is a perspective view of a base for a fan;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a side elevation view thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan view thereof.

The broken line showing of environmental structure in FIGS. 1-5 is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a base for a fan, as shown and described. 